Characteristics of Birds Reference Chapters 1-2

ADVANCED LEC 02 University of Rio Grande Donald P. Althoff, Ph.D. ORNITHOLOGY Characteristics of Birds Reference Chapters 1-2

Characteristics of Birds Result in… • Efficient mode of _________________ • Further ______________(i.e., higher levels of process some sensory input) • Promote _____________ • Increased ______________efficiency • Improved senses of _______and ________

FLIGHT Accomplished by being able to…. • __________ • __________ • ________________ under adverse conditions Graham Owen Gallery

Flight: KEY STRUCTURES • ________ • Feathers • Feathers • Feathers • Feathers ___________ • ….and some _____________

Perfection of ENDOTHERMY • Allows activity under _______environmental conditions • Specialization of __________anatomy (i.e., wings & feet have enabled efficient use of this bigger activity window)

Birds arose from _________STOCK Similarities to reptiles include…. • ____occipital condyle (mammals have 2) • Lower mandible articulates with movable _________ bone (mammal’s lower mandible hinged directly to skull—at least for many species) • Ears have _______bone

Single “ear bone” (common to birds, amphibians, reptiles, and

Key MORPHOLOGICAL trends towards… • Overall, a ______skeletal structure --transformed wrist and shoulder --”some” hollow bones (as noted) --evolution of the bastard wing—or ______, which prevent _________at low speeds • Muscular design that provided a __________ that could produce the main components of flight: _____________

A) Steep angle of attack w/o ALULA B) Steep angle of attack with ALULA Gill Fig. 5.5 (p121): The slot created by the extended alula keeps the airflow close to the wing during takeoff and landing.

alula

Key characteristics….that were improvements over reptilian stock… 1 • Feathers • Wings • Lightness • _____________________ • _______________–must make “quick” adjustments in focus because one is often moving faster • _______________ • _______________ • _________________________ • _________________________ 2 3 4 5 6 7 8 9

Feathers • _____________air-resistance • Control heat loss (hot conditions) /retention (cool conditions (i.e., ______________) • ____________________ • Wings—conquer air space * read Gill p40: what is difference between _________ theory vs. _________ theory for development of forelimbs into wings?

Lightness • Feathers: “the” __________materials for their size and weight known ! ! ! • No _________ nor _____________ • No ________(….forget about the egg tooth!) • _______________________ bones

Lightness…con’t • Radical _________ of intestines • __________of urinary bladder • ________(sacs) in bones, body cavity, and elsewhere

Centralization & Balance • All locomotor muscles toward body’s _____________…wings controlled by _________strings • Gizzard (in lieu of teeth) and other abdominal organs in _______________

Visual Acuity • ______eyes • _______ field of vision • Remarkable________ determination • Brain with enlarged ______ and __________ centers

Respiratory System • ____________ of fresh air over lung surfaces • Lungs _________________with each breath (unlike mammals) ________…ensuring lost of incoming O2 and outgoing CO2 • No diaphragm—meaning less weight, too

Rapid Circulation & O2 Carrying Capacity • Increased heart rate • Blood stream O2 carrying capacity greatly increased red corpuscles (____________) are _________________ (unlike mammals)-- more ___________ blood per cubic millimeter

Limited Body Fluids & Excess Weight • With rapid exchange of air via respiratory system, ____________ needed for cooling • Highly sensitive diet with _________________ & ____________________ substances ...except for the hoatzin, there are no true ruminating birds. Few species are consistent “grazers” (i.e, year-round)

Feathers…again • _________ to birds—no other vertebrates have structure similar to a feather • Different _____of feathers for _______________

Feathers: Functions…again…plus… • Efficient flight • Thermoregulation • _______________ • _____________(some species) • ____________/mating displays and attraction

Feathers con’t • Feathers are “_______” • __________growths of skin • Develop from ___________ (like mammal hair) • _____________coloration vs. _____________coloration From Pettingill 1985 Fig. 20

Feathers con’t • Feathered areas: ________ • Unfeathered areas: ________ • Counts: __types __tracts • Number: ____hummingbird ______tundra swan

Other Coverings • _______on bill • _______on feet (reptile-like) • _______on toes ALL of these have ______in skin (aka integument)

Reproduction • ____________…link to reptiles • _________________ care… advanced over reptiles • High potential for ___________ a) _______clutches b) _______clutches c) ___________ • capabilities

Characteristics of Birds Reference Chapters 1-2